Oslo Cathedral — formerly Our Savior’s Church — is the main church for the Church of Norway Diocese of Oslo, as well as the parish church for downtown Oslo. The present building dates from 1694-1697. The Norwegian Royal Family and the Norwegian Government use the Cathedral for public events. It was closed for renovation in August 2006 and re-opened with a festive high mass on 18 April 2010.

More details: https://en.wikipedia.org/wiki/Oslo_Cathedral